Oh wow, I didn't know that website existed--I'm definitely bookmarking it, as I'm curious about that kind of data and I lose track mentally of which companies have bought bitcoin and how much, etc. Thanks for including that link in your post, OP.
Now, a very common logic, which institution would like to buy btc at $100k or even at million dollars when the seller institution is already taking out big profits in fiat by selling their btc to the buyer Institution? Won't that btc be coming with an impermanent loss if the price dumps later?
I'm not sure I fully understand your question--nobody knows how high bitcoin is going to go, so it isn't necessarily true that buying it at a price of, say, $100k would be screwing the buyer by guaranteeing them a loss. Nor do I think that there need to be big buyers at the ready in order for any of these corporations to sell their bitcoin. It's quite possible to sell a huge amount over an extended period of time, which is exactly how mutual funds or other big investors sell huge chunks of stock. They don't just dump it all on the market at once, since that would drive the price down. Nor do they have to sell everything all at once to another buyer.